Portable work bench

ABSTRACT

An improved portable work bench includes a structural body, and a platform disposed on and frictionally contacting the structural body. In addition, the platform includes an override mechanism for allowing horizontal movement of the platform along the structural body. Further, the portable work bench may include a plurality of legs for supporting the structural body. The structural body may be tubular and preferably has a trapezoidal cross-section. Such work bench can be used by disposing the platform on the structural body, so that the platform frictionally contacts the structural body. Then the user can mechanically override the static friction between the platform and the structural body and move the platform horizontally along the structural body.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of application Ser. No. 09/207,355, filed Dec. 8,1998, which is a continuation-in-part of application Ser. No.08/899,937, filed Jul. 24, 1997, now U.S. Pat. No. 5,875,828.application Ser. No. 09/207,355 also derives priority from U.S.application Ser. No. 60/070,501, filed Jan. 7, 1998, now abandoned.

FIELD OF THE INVENTION

This invention relates generally to work benches and more particularlyto a portable work bench that can support a power tool and a workpiece.

BACKGROUND OF THE INVENTION

It is common in the construction industry for users to bring their powertools to the work site. Thus, the users require a work surface at thework site to support the power tools for use. Preferably the worksurface is at a certain height so that the user can comfortably use thepower tool. In addition, the work surface should also be sufficientlyportable to be easily moved around a work site.

In the past, users have disposed their power tools on sheets of woodwhich are in turn supported by two or more sawhorses. This arrangement,however, lacks the strength for efficient operation, as well as beingdifficult to move around the work site.

Accordingly, different support stands or work benches have been proposedin order to provide a portable work surface that can support a powertool. Some of these prior art solutions have been described in U.S. Pat.Nos. 1,864,840, 4860,807, 4,874,025, 4,974,651, 5,193,598, and5,421,231. However, these prior art solutions do not provide a platformsupporting the power tool which can be moved horizontally so that thepower tool can be moved without moving the workpiece. Other prior artsolutions, such as the one described in U.S. Pat. No. 5,592,981, providea platform supporting the power tool which can be moved horizontally sothat the power tool can be moved without moving the workpiece. However,they require that the user insert and slide the platform from the end ofthe workbench towards the desired position on the workbench.

SUMMARY OF THE INVENTION

In accordance with the present invention, an improved portable workbench is employed. The portable work bench includes a structural body,and a platform disposed on and frictionally contacting the structuralbody. In addition, the platform includes an override mechanism forallowing horizontal movement of the platform along the structural body.Further, the portable work bench may include a plurality of legs forsupporting the structural body. The structural body may be tubular andpreferably has a trapezoidal cross-section.

Such work bench can be used by disposing the platform on the structuralbody, so that the platform frictionally contacts the structural body.Then the user can mechanically override the static friction between theplatform and the structural body and move the platform horizontallyalong the structural body.

Another embodiment of the present invention discloses a portable workbench, which includes a structural body, and a platform disposed on thestructural body. In addition, the platform includes a cam mechanism forlocking the position of the platform along the structural body. Further,the portable work bench may include a plurality of legs for supportingthe structural body. The structural body may be tubular and preferablyhas a square cross-section.

Additional features and benefits of the present invention are described,and will be apparent from, the accompanying drawings and the detaileddescription below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate preferred embodiments of theinvention according to the practical application of the principlesthereof, and in which:

FIG. 1 is a perspective view of a first embodiment of a portable workbench of the present invention;

FIG. 2 is a cross-sectional side view of the work bench along line 2-2of FIG. 1;

FIGS. 3A and 3B are cross-sectional front views of the work bench alongline 3-3 of FIG. 2, showing a first override mechanism;

FIGS. 4A and 4B are detailed cross-sectional side views of the workbench along line 2-2 of FIG. 1;

FIGS. 5A and 5B are cross-sectional front views of the work bench alongline 3-3 of FIG. 2, showing a second override mechanism;

FIGS. 6A and 6B are cross-sectional front views of the work bench alongline 3-3 of FIG. 2, showing a third override mechanism;

FIG. 7 is a perspective view of a second embodiment of a portable workbench of the present invention;

FIG. 8 is a cross-sectional side view of the work bench along line 8-8of FIG. 7;

FIG. 9 is a front view of the work bench of the present invention withadditional attachments and extensions;

FIG. 10 is a perspective view of a portable work bench of the presentinvention;

FIG. 11 is a cross-sectional side view of a first embodiment of the workbench along plane II-II-II of FIG. 10; and

FIG. 12 is a cross-sectional side view of a second embodiment of thework bench along plane II-II-II of FIG. 10.

DETAILED DESCRIPTION

The invention is now described with reference to the accompanyingfigures, wherein like numerals designate like parts. Referring to FIG.1, a portable work bench 10 of the present invention is shown carrying achop saw 100. However, persons skilled in the art will recognize thatthe work bench 10 can support any power tool, such as a sliding compoundmiter saw, a drill press, a table saw, etc., any hand tools, or anythingelse that needs to be supported.

The work bench 10 has a structural body 11 and a platform 12 disposed onand frictionally contacting the structural body 11. In addition, thework bench 10 may have legs 13 for supporting the structural body 11 andplatform 12. The legs 13 may be connected to the body 11 via brackets 14as is well known in the art. Persons skilled in the art are referred toU.S. Pat. Nos. 4,605,099 and 5,592,981, which disclose exemplary meansfor providing foldable legs for the work bench. However, persons skilledin the art will know that fixed legs which do not fold will alsofunction properly.

Referring to FIG. 2, the structural body 11 is preferably tubular sothat it can withstand substantial amounts of torsional and lateral loadsapplied thereto. Furthermore, the cross-section of the structural body11 is preferably trapezoidal, that is, the top 11 t and bottom 11 bsurfaces of the body 11 are parallel to each other. The side surfaces 11s can be parallel to each other, but are not required to. Preferably,the side surfaces 11 s are angled in relation to the top 11 t and bottom11 b surfaces. One side surface may be at an angle A relative to the top11 t and bottom 11 b surfaces, while the other side surface may be at anangle B relative to the relative to the top 11 t and bottom 11 bsurfaces. Preferably both angles A and B are equal and could be between0° and 15°, where the preferred range is 3° to 4°.

The platform 12 is preferably designed to receive a power tool 100thereon in the manner well known in the art. As mentioned above, theplatform 12 is disposed on and frictionally contacts the structural body11. As seen in FIG. 2, the side surfaces 12 s of the platform 12 contactthe side surfaces 11 s of the body 11. Once the power tool 100 is placedon the platform 12, the frictional contact will hold the platform 12 onthe body 11, as well as maintain the location of the platform 12 alongthe body 11. In other words, because of the frictional contact betweenthe platform 12 and the body 11, a user may not be able to easily movethe platform 12 along the body 11. In addition, if the body 11 has atrapezoidal cross-section, the platform 12 may stay on the body 11 whena sideways force F is applied on the platform, without requiring aseparate lock assembly to hold the platform in place.

It is also preferable to provide respective flat foot portions 12 f onthe platform side surfaces 12 s. This enables a user to lift up theplatform 12 and use the platform on a table or other flat surface, ifdesired.

The platform 12 may also have an override mechanism 20. This overridemechanism 20 allows the user to move the platform 12 along the length ofthe structural body 11. FIGS. 3, 4, 5, and 6 show different overridemechanisms to accomplish this purpose. All of these override mechanismslift the platform 12 so that the platform side surfaces 12 s do notcontact the body side surfaces 11 s. Because the frictional contact isreduced, the user can then roll or slide the platform to the desiredposition using less force than before.

Referring to FIGS. 3 and 4, a carriage 23 is disposed under the platform12. The carriage 23 may have rollers 24 rotatably attached thereto.Persons skilled in the art will realize that other friction reducingmechanisms, such as ball bearings, may be used instead. As seen in FIGS.3A and 4A, the rollers 24 do not touch the structural body 11.Furthermore, the carriage 23 is preferably connected to the platform 12via springs 31, which pull the carriage 24 towards the platform 12.

A threaded shaft 28 is threadedly engaged to the platform 12. The shaft28 may in turn have a pad 30, which contacts the carriage 23. Further,the shaft 28 may have a pinion 29, which in turn engage the rack 33 ofrod 27.

The override mechanism 20 may have a lever 21 pivotally attached to boththe platform 12 (via pin 25) and to the rod 27 (via pin 26).Accordingly, when the user moves the lever 21 in a clockwise directionX, the lever 21 pivots about pin 25, pulling rod 27. As the rod 27 ispulled, the rack 33 and pinion 29 combination cause the shaft 28 torotate. As the shaft 28 rotates, it screws out of platform 12, pushingcarriage 23 downward. As the carriage 23 moves downward, the rollers 24contact the structural body 11. Then the platform 12 begins to risealong direction Y, until a gap is created between the platform sidesurfaces 12 s and the structural body side surfaces 11 s (see FIG. 4B).

Because the platform side surfaces 12 s and the structural body sidesurfaces 11 s do not contact each other, no friction exists betweenthem. A user can then easily move the platform 12 along the structuralbody 11 by pushing the platform 12. Because the rollers 24 contact thestructural body 11, less force is required to move the platform 12 thanbefore, as the coefficient for rolling friction is smaller than thecoefficient for sliding friction.

Once the platform 12 has been moved to the appropriate location, theuser can rotate the lever 21 in a counterclockwise direction. Thiscauses the carriage 23 to return to the original, retracted position, inturn lowering the platform 12 until the platform side surfaces 12 s andthe structural body side surfaces 11 s contact each other.

In order to ensure that the carriage 23 does not move sideways or rotatewhen the lever 21 is rotated, it is preferable to slidably dispose thecarriage 23 on rods 41, which are fixedly attached to the platform 12.The rods 41 ensure that the carriage 23 only moves up and down.

A second embodiment of the override mechanism 20 is shown in FIG. 5. Asdescribed above, the override mechanism 20 may preferably have acarriage 23 with rollers 24 rotatably attached thereto. In addition, thecarriage 23 may be slidably disposed on rods 41, which are fixedlyattached to the platform 12. In addition, springs 31 preferably bias thecarriage 23 towards the platform 12.

Unlike in the previous embodiment, cams 46 are used to move the carriage23 downward. The cams 46 are pivotably attached to the platform 12 androtate about pin 44. The cams also have camming surfaces 45 and levers43. When the user pivots the cams 46 via the levers 43, the cammingsurfaces 45 contact and urge the carriage 23 downwardly, so that therollers 24 contact the structural body 11 and lift the platform 12therefrom. In order to lower the platform 12, the user need only torotate the levers 46 in the opposite direction.

A third embodiment of the override mechanism 20 is shown in FIG. 6. Asdescribed above, the override mechanism 20 may preferably have acarriage 23 carrying rollers 24 rotatably attached thereto. In addition,the carriage 23 may be slidably disposed on rods 41, which are fixedlyattached to the platform 12. In addition, springs 31 preferably bias thecarriage 23 towards the platform 12.

Unlike in the previous embodiments, a rod 51 is rotated via knob 50 inorder to move the carriage 23 along rods 41. Rod 51 has a pinion 56disposed thereon. Pinion 56 in turn meshes with a rack 55 provided on ashaft 53. Once the knob 50 is rotated, the rack 55 and pinion 56 mesh,causing the shaft 53 to move downwardly. The shaft 53 then moves thecarriage 23 downwardly. Preferably, a spacer 54 is provided in theplatform 12 to ensure that the shaft 53 will only move vertically.Further, it is also preferable to provide a spring 52 which biases theshaft 53 towards the platform 12.

Referring to FIG. 7, a second embodiment of the portable work bench isdesignated with reference numeral 10′. Like the previous embodiment,work bench 10′ has a structural body 11 and a platform 12 disposed onand frictionally contacting the structural body 11. In addition, thework bench 10 may have legs 13 for supporting the structural body 11 andplatform 12.

The platform 12 may also have an override mechanism, allowing the userto move the platform 12 along the length of the structural body 11.FIGS. 7 and 8 show different aspects of another override mechanism usedto accomplish this purpose. Preferably, the structural body 11 has arack 61 along its entire length. The platform 12, in turn, has a crankwheel 62, connected to a rod 63. Rod 63 has a pinion 64 disposedthereon. Pinion 64 meshes with the rack 61. The platform 12 may alsohave rollers 24 disposed thereon.

By turning the knob 50, the pinion 64 rotates, meshing with the rack 61,thus overriding the static friction between the platform 12 and thestructural body 11 and moving the platform 12 along the length of thestructural body 11. Persons skilled in the art may recognize that aproper ratio between the pinion and rack teeth can be selected in orderto produce a mechanical advantage to help the user to move the platform12 along the length of the structural body 11.

Persons skilled in the art should also recognize that a lock mechanismcan be provided to lock the crank wheel in order to prevent unintendedmovement of the platform 12. Such persons will recognize that exemplarycrank wheel lock mechanisms exists, for example, in the table saw field.

In addition, persons skilled in the art will recognize that extensionscan be added to the portable work bench as is well known in the art.Referring to FIG. 9, extension 70 can be inserted into the structuralbody 11 in order to increase its length, allowing the user to move theplatform 12 along a greater length. Preferably, extension 70 has thesame cross-section as the structural body 11. Extension 70 preferablyhas a fixed inner joint 71, which can be inserted into the structuralbody 11. The joint 71 can then be secured by means of a screw or pinassembly 72.

A workpiece support mechanism 80 can also be used on the work bench.This mechanism can support an elongated workpiece, such as moldings,etc., so that the user can cut it accurately.

The support mechanism 80 has a bar 73, which is slidably attached to thestructural body 11. A clamp assembly 75 is disposed at the end of bar73. The clamp assembly 75 slidably receives and clamps a bar 74. Asupport end 74 a is in turn disposed at the end of bar 74. Accordingly,a user can adjust the bar 74 and support end 74 a, and then adjust thebar 73 so that the workpiece is properly supported.

FIGS. 10-12 show another embodiment of the present invention, whereinlike numerals designate like parts. As before, the structural body 11 ispreferably tubular so that it can withstand substantial amounts oftorsional and lateral loads applied thereto. Furthermore, thecross-section of the structural body 11 is preferably square.

The platform 12 is preferably designed to receive a power tool 100thereon in the manner well known in the art. As mentioned above, theplatform 12 is disposed on the structural body 11. As seen in FIG. 11,the platform 12 may contacts the top and rear surfaces of the body 11.Platform 12 may also contact the bottom surface of the body 11 via ahook portion 12 h.

Platform 12 may also have a cam 15 pivotally attached thereto andpivotable about axis P. A handle 16 is connected to cam 15 so that, uponmovement of handle 16, cam 15 moves.

In addition, platform 12 may have a locking plate 17 pivotally attachedthereto and pivotable about axis H. Locking plate 17 may pivot between afirst position contacting the structural body 11 and a second positionnot contacting the structural body 11. A spring 18 may be connectedbetween locking plate 17 and platform 12 to bias locking plate 17towards the second position.

In order to lock platform 12 on the desired position along structuralbody 11, the user need only move handle 16 along direction C. This willcause cam 15 to rotate and bring cam portion 15 c against locking plate17. As cam 15 is rotated, the locking plate 17 is moved further towardsthe first position until it contacts structural body 11. Locking plate17 may have a hook portion 17 h to further contact the structural body11 when in the first position. To unlock platform 12, the user need onlymove handle 16 in the opposite direction.

Persons skilled in the art will recognize that the same result, i.e.,locking platform 12 on a desired position along structural body 11, maybe achieved without locking plate 17 and spring 18, as shown in FIG. 3.Instead, cam 15 will contact structural body directly.

Persons skilled in the art may recognize other additions or alternativesto the means disclosed herein. However, all these additions and/oralterations are considered to be equivalents of the present invention.

1. A portable workbench comprising: a tubular structural body having alongitudinal axis and having a width and a length longer than the width;a plurality of legs supporting the structural body a platform disposedon the structural body and contacting the structural body on at leasttwo sides; and a locking mechanism disposed on the platform for fixingthe position of the platform relative to the structural body, saidlocking mechanism comprising an eccentric cam rotatable about a firstaxis between a first position locking the platform on the structuralbody and a second position unlocking the platform. 2-3. (canceled) 4.The work bench of claim 1, wherein the structural body has a trapezoidalcross-section.
 5. The work bench of claim 1, wherein the platformfurther comprises a top surface, upon which a power tool can beinstalled thereon.
 6. The work bench of claim 1, wherein the platformfurther comprises side surfaces that frictionally contact the structuralbody.
 7. The work bench of claim 6, wherein the side surfaces end inrespective flat foot portions. 8-12. (canceled)
 13. The work bench ofclaim 1, further comprising an extension that can be installed at an endof said structural body.
 14. The work bench of claim 1, furthercomprising a support mechanism installed at an end of said structuralbody for supporting an elongated work piece.
 15. The work bench of claim1, wherein the structural body has a square cross-section. 16-17.(canceled)
 18. The work bench of claim 17, wherein the platform ismovable along the structural body.
 19. (canceled)
 20. The work bench ofclaim 19, wherein the first axis is substantially parallel to thelongitudinal axis of the structural body.
 21. The work bench of claim17, wherein the platform comprises a hook portion contacting thestructural body.
 22. The work bench of claim 17, wherein the lockingmechanism further comprises a plate disposed between the cam and theother of the structural body and the platform.
 23. The work bench ofclaim 22, wherein the locking mechanism further comprises a spring forbiasing the plate towards the cam.
 24. The work bench of claim 1,further comprising a handle connected to the cam for moving the cambetween first and second positions.
 25. The work bench of claim 1,wherein the first axis is substantially horizontal.